Current advice for strong wet diopter with Sony 16-50

[polyroly 7]

There seem to be a few new options for wet lenses since last I looked. I am looking for advice on a good choice for use with the Sony kit 16-50mm housed in the SaltedLine Macro Port (67mmThread). I am currently using an Inon 165 (7x about) with my old RX100M2 but have just set up with a Sony A6400 and I want to get familiar with the kit camera with a short port before venturing to the world of longer ports for use with a 90mm Macro.

Anyone with favorable comments with a lens +14 up - I would love to get some advice. Thanks!

[ChrisRoss 150]

The issue with strong diopters on zooms like the 16-50 is limited working distance and range.  The Nauticam CMC-1 will give 0.9x magnification at a working distance of 46mm in Nauticam's port, the sea frogs will be similar.  It only focuses between 46 and 74mm from the front of the lens, meaning lighting and framing may be challenging.  The INON lenses are said to give a little more working room.  The INON UCL-67 is slightly more powerful than the CMC-1 and the UCL-90 and CMC-2 are similar power.

The CMC-1 gives 0.9x while the CMC-2 achieves 0.7x but with more working distance and range (69 - 121mm).

Interceptor 121 reviewed a few lenses on m43, the results are not directly applicable to the Sony sensor but the relative magnifications will be the same.  https://wetpixel.com/articles/review-wet-close-up-lenses

[polyroly 7]

Oh, ok thanks Chris, I really am unsure of these numbers, and when put in context of the things I have been trying to get my head around with domes, curvature, and virtual images I was thinking each camera lens and port glass distance would result in a different recommendation. So there are threads on this matter, with different lens set-ups - that I can sort of use as a guide, like Interceptor121's .

I was rather thinking that with the Sony kit lens I would need one of the stronger offerings, but maybe not. Even the CMC-1 lists at 4.5x and the UCL lists at +15 or 2.76x (?) but there are some others listing well over 20x (and costing a pretty penny) and then some people talk of stacking - I must say - it boggles.

[ChrisRoss 150]

4 minutes ago, polyroly said:

Oh, ok thanks Chris, I really am unsure of these numbers, and when put in context of the things I have been trying to get my head around with domes, curvature, and virtual images I was thinking each camera lens and port glass distance would result in a different recommendation. So there are threads on this matter, with different lens set-ups - that I can sort of use as a guide, like Interceptor121's .

I was rather thinking that with the Sony kit lens I would need one of the stronger offerings, but maybe not. Even the CMC-1 lists at 4.5x and the UCL lists at +15 or 2.76x (?) but there are some others listing well over 20x (and costing a pretty penny) and then some people talk of stacking - I must say - it boggles.

The problem is everyone has different ways of labelling the strength of the diopter.  When it comes down to it the Nauticam port charts show you directly what you get in image magnification on sensor.  Plus they also indicate working distance which allows you to see how easy they will be to use in terms of framing and lighting.  That is a starting point.

Next Interceptor's tests rank the lenses in strength, the UCL-67 being stronger than the CMC-1 then UCL-90 and finally CMC-2.  the same order will be apparent when using with the Sony lens.  In general as you go up in strength working distance reduces as all the lenses do is let you focus closer.  There is some variation in working distance between brands and apparently INON lenses have a touch more working distance. 

The minimal working distance makes lighting a challenge - plus until you get in the right range there's only a blur to see through the viewfinder you have to move in until you can recognize something.  With the macro lens you can focus further out and move in progressively focusing as you go.

In general the working distance is pretty minimal.  the 16-50 plus CMC-1 gives 0.9x with 46mm working distance.  The 90mm macro however gives 1.0x with 130mm working distance and focuses all the way from 1.0x to infinity.  In general the macro lenses are much easier to use than diopters.